The Fp (Infrequency-Psychopathology) Scale
Because the F scale is typically elevated among psychiatric patients, it is often difficult to differentiate between persons with true psychopathology and those who have some psychopathology but are nonetheless faking bad. This is particularly true if the psycho- pathology is quite severe. The history of the person (e.g., degree of preexisting psycho- pathology) and context of the referral (e.g., possible gain for faking bad) can often be quite useful in making this distinction. To further assist with this differentiation, Ar- bisi and Ben-Porath (1995) developed a set of 27 items that were infrequently answered even by psychiatric inpatients. (In contrast, the F scale was developed from infre- quently answered questions by the normative sample.) This means that high scores on Fp (T> 106 for men and T> 113 for women) can potentially identify persons who are faking bad even if they are psychiatric patients (Arbisi & Ben-Porath, 1998; R. Rogers, Sewell, & Ustad, 1995).